<!DOCTYPE html>
<html>

	<head>
		<meta charset="utf-8" />
		<title></title>
		<!--[if lt IE 9]><!-->
		<script src="http://code.jquery.com/jquery-1.11.3.min.js "></script>
		<!--<![endif]-->
		<!--[if gte IE 9]><!-->
		<script src="https://code.jquery.com/jquery-3.2.1.min.js "></script>
		<!--<![endif]-->
		<script>
			$(document).ready(function() {
				function aniDiv() {
					$("div:eq(0)").animate({
						width: "50%"
					}, "slow");
					$("div:eq(0)").animate({
						width: "100%"
					}, "slow", aniDiv);
				}
				aniDiv();
				$(".btn1").click(function() {
					$(":animated").css("background-color", "red");
				});
			});
		</script>
	</head>

	<body>
		<button class="btn1">修改动画元素颜色</button>
		<div style="background:blue;">Div 1</div>
		<div style="background:green;">Div 2</div>
		<div style="background:yellow;">Div 3</div>
	</body>

</html>